1. Field
Apparatuses and methods consistent with exemplary embodiments relate to a roller used in an image forming apparatus, and more particularly, to a roller including a coating layer for improved durability.
2. Related Art
In general, electrophotographic image forming apparatuses such as a laser printer, a facsimile, or a copy machine may include photoreceptor, and a charging roller, a developing roller, and a transfer roller which are installed in a circumference of the photoreceptor, and the like. A developing agent supplied from a developing device may move by voltages applied to the photoreceptor, the charging roller, the developing roller, and the transfer roller, and thus a certain image may be formed in a printing medium.
For example, the charging roller may charge a surface of the photoreceptor to a certain voltage, and light scanned from the exposure unit may form an electrostatic latent image corresponding to printing data on the charged surface of the photoreceptor. The developing roller may supply the developing agent to the photoreceptor so that the electrostatic latent image may be developed to an image by the developing agent. The image by the developing agent may be transferred onto the printing medium passing between the photoreceptor and the transfer roller through the transfer roller.
The developing roller and the charging roller may be core parts which move and charge a toner as described above, and precise parts which have characteristics such as low surface roughness, a low surface fiction coefficient, uniform electrical conductivity, high elasticity, and low hardness.
In high-end laser printers, since the number of developing sheets which is twice more than that in low-end printers is needed, the durability of the developing roller and the charging roller is further important. Accordingly, there is a need for surface coating technology development for maintaining characteristics required in the developing roller and the charging roller and improving the durability of the surfaces thereof.